Calcium-fortified, grape-based products and methods for making them

ABSTRACT

Methods of making a calcium fortified, tartaric acid-containing product that is essentially free of tartrate precipitates. The tartaric acid concentration of a precursor is adjusted to form an adjusted precursor. An additive comprising a calcium-based compound is mixed with the adjusted precursor to make the fortified product. The compound may be calcium gluconate, a variety of other compounds or mixtures thereof. The fortified product, when stored at approximately 70° F., may remain essentially free of tartrate precipitate for at least sixteen weeks.  
     The fortified, tartaric acid-containing products processed by the disclosed methods.

RELATED U.S. APPLICATION(s)

[0001] This application claims priority from U. S. ProvisionalApplication Serial No. 60/183,299, filed Feb. 17, 2000, and U.S. patentapplication Ser. No. 09/788,327, filed Feb. 16, 2001, both of which arehereby incorporated herein by reference.

TECHNICAL FIELD

[0002] The embodiment relates to formulation of grape-based productssuch as, but not limited to, juice, juice-blended beverages, and winecontaining a significant amount of bioavailable calcium as well as toprocesses for the manufacture of the products. The field encompasses theproduction, storage and distribution of stable calcium-fortified purple,red and white grape juice and juice drinks, in shelf-stable,refrigerated, frozen and concentrate forms. Beverages covered includegrape-based liquids blended with non-grape liquids.

BACKGROUND ART

[0003] Calcium is an essential mineral in the human diet for thepreservation of human health. Calcium has been established as a keynutrient for skeletal rigidity; it is also known to impact metabolic,muscular, neurological, circulatory, and enzymatic processes. Calciumdeficiency is a contributing cause of osteoporosis, a debilitating bonedisease marked by a loss of bone mass.

[0004] Calcium is naturally found in many foods. The primary source ofbioavailable calcium is milk and, more generally, dairy products. Aspeople enter early adulthood, their consumption of dairy products tendsto decrease. This may lead to a state of chronic calcium deficiency.This trend is particularly found with young women and could contributeto their high rates of osteoporosis development in later life.Additionally, many people are, or become, lactose intolerant as theyage, thus reducing their ability to obtain natural, traditionally richsources of this mineral.

[0005] Therefore, many alternate sources of food, drink, and supplementsare currently being fortified with various organic and inorganic calciumsalts. These alternate sources include pills, powders, food products, aswell as a variety of fruit and non-fruit based juices and beverages.Many plaguing problems surround the provision of organoleptic qualitiesand bioavailability of these calcium-fortified sources. A commoncomplaint with respect to fortified beverages is the relativeinsolubility of some of the added calcium salts, intolerableprecipitation of solids, and a “chalky” feeling in the mouth upondrinking. Additionally, undesirable flavors and shelf instabilitycontribute to a poor food product.

[0006] The fortification of various liquids with calcium, includingorange, apple and other lo juices and beverages is an art currentlypracticed by juice and beverage manufacturers. Patents describingcalcium fortification of fruit juices include several granted to Heckertand assigned to the Proctor and Gamble Company (for example, U.S. Pat.No. 4,722,847). These patents disclose calcium-citrate-malate (CCM)technology and teach that various calcium citrate and malate compounds,when combined in accordance with disclosed processing methods, willproduce stable, fortified juices containing calcium levels at leastequivalent to those normally occurring in milk (i.e., 350 mg/8 fl. oz).

[0007] U.S. Pat. No. 4,740, 380 to Melachouris et al. discloses acalcium-fortified acidic beverage formulated using various calciumsources. U.S. Pat. No. 6,106,874 to Liebrecht et al. discloses acalcium-fortified nutritional beverage, which can be made from singlestrength juice. Calcium sources therein are natural milk mineral andGluconal CAL® (manufactured by Glucona America).

[0008] Calcium fortification of grape-based beverages is especiallychallenging. The predominant organic acid in grape-based liquid (e.g.juice, wine, etc.) is, uniquely among fruit-derived liquids, tartaricacid. At pH levels above 2.8, tartaric acid will chemically dissociateinto tartrate, bitartrate and hydrogen ions. As the pH of grape juiceincreases, the dissociation of tartaric acid becomes progressively morefavored. Across the typical pH range of about 2.8 to about 3.9 forpurple, red and white grape juices from Vitis labrusca, V. vinifera, andV. labrusca×V. vinifera hybrid grapes, the availability of tartrate ionsfor reaction with any added calcium to form insoluble crystallinecalcium tartrate, is very high. Indeed, at relatively high pH andwithout the presence of calcium, potassium bitartrate crystals or“argot” in juice (or “wine stones” in wine) may be formed due to thenaturally occurring concentration of potassium in grape-based product.This is commonly found in winemaking and the pertinent literature isabundant in addressing ways to solve this problem.

[0009] The formation of calcium tartrate crystals in grape-based liquidsis known from past research on wines. This formation is dependent, forexample, on the pH of the beverage, the storage temperature of thecalcium plus beverage mixture, the presence of inhibitors, the ionicstrength of solution, agitation of solution, and the length of time thatthe mixture is held in storage. Abgueguen and Boulton, (1993); McKinnon,1993. Formation of calcium tartrate crystals may occur instantly uponthe cooling of a pasteurized juice-calcium mixture, Alternatively,crystals may not occur for a substantial period of time. However,because calcium tartrate crystals have very low solubility in aqueoussolutions such as grape juice, once formed, these crystals will tend toremain as an insoluble precipitate rendering the beverageorganoleptically unacceptable with significantly diminished bioavailablecalcium. After initial nucleation of these crystals, they will generallygrow in size until the point of solution saturation is reached.

SUMMARY OF THE INVENTION

[0010] In accordance with a first embodiment of the present invention, amethod of making a fortified, tartaric acid-containing product isprovided. The product is fortified with a predetermined amount ofbioavailable calcium and the product is essentially free of tartrateprecipitates. A tartaric acid-containing precursor is provided. Theconcentration of tartaric acid in the precursor may be betweenapproximately 0.005 g per 100 mls and approximately 1.31 g per 100 mls.The precursor may be a grape-based liquid and may be derived fromcolored or white grapes. The predetermined amount of bioavailablecalcium may be between 8% and approximately 35% of required daily intakefor a human. The tartaric acid concentration of the precursor isadjusted to form an adjusted precursor. In an embodiment, the measured,adjusted tartaric acid concentration might be no greater than 0. 17 gper 100 mls. An additive comprising a calcium-based compound is mixedwith the adjusted precursor to make the fortified product. The compoundmay be calcium gluconate, a variety of other compounds or mixturesthereof. The fortified product, when stored at approximately 70° F. mayremain essentially free of tartrate precipitate for at least sixteenweeks.

[0011] In other embodiments, fortified, tartaric acid-containingproducts processed by the methods described above are provided.

[0012] In a further embodiment, another method of making a fortified,tartaric acid-containing product is provided. In this embodiment, theprecursor has between approximately 0.005 g per 100 mls andapproximately 0.26 g per 100 mls of tartaric acid. The precursor ismixed with a predetermined amount of calcium gluconate. The bioavailablecalcium in the resulting product is no more than approximately 20% ofrequired daily intake of calcium for a human. In further embodiments,the resulting product is provided.

[0013] The adjusted precursor may be formed by adding a second precursorto a liquid tartaric acid-containing precursor. The second precursor maybe single strength juice. Water may alternatively be added duringadjustment; the adjusted tartaric acid concentration might be no greaterthan approximately 0.08 g per 100 mls. The calcium-based compound may becalcium lactate.

[0014] In yet another embodiment, a method is provided to make afortified, tartaric acid-containing product with bioavailable calcium inan amount equaling approximately 35% of required daily intake for ahuman. The tartaric acid concentration of a precursor derived fromcolored grapes is adjusted to form an adjusted precursor and calciumgluconate is mixed with the adjusted precursor.

[0015] In yet another embodiment, a method is provided to make afortified, tartaric acid-containing product with bioavailable calcium inan amount equaling between approximately 8% and approximately 35% ofrequired daily intake for a human. The tartaric acid concentration of aprecursor derived from white grapes is adjusted to form an adjustedprecursor and calcium lactate is mixed with the adjusted precursor.

[0016] Still other embodiments provide product made by both of thelatter embodiments.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0017] As noted previously, pH, storage temperature, presence ofinhibitors and solution storage time all contribute to calcium tartratecrystal formation in grape-based beverages and liquids. Embodiments ofthe present invention detailing methods of making fortified grape-basedproducts and the products themselves are based upon the need to controltartaric acid concentration, the amount and source of calcium-basedadditive, and the presence of sequestrants. Understanding theinter-relationships between the many factors are important in creating acalcium-fortified product containing juice or other derivativecomponents of grapes.

[0018] As used in the specification and appended claims, the term“beverage,” “juice,” and “liquid” are all being used interchangeably andrefer to any commonly available juice-type product which includes, butis not limited to, single strength (abbreviated SS), ready-to-drinkproducts, concentrates (frozen and shelf-stable), cocktails and thelike. As used herein, “single strength” refers to a juice, which has anapproximate Brix value that is required by its standard of identity(which is based on 21 CFR 101.30). As used herein, “precursor” usuallyrefers to a natural fruit source of tartaric acid but may be anytartaric acid-containing starting material intended to becalcium-fortified. As used herein, “stable” and “shelf-stable” are usedessentially interchangeably and refer to a product which can maintainorganoleptic and nutritional quality (including maintaining thebioavailability of calcium) for an extended timeperiod. This period may,but is not limited to, a total time of processing, warehousing,shipping, retailing, and “at consumer” storage. This total time isgenerally, but not limited to, about 26-52 weeks.

[0019] Embodiments are dependent on providing a tartaric acid-containingprecursor. Such precursors are the components of concern due to thelikelihood of the adverse formation of tartrate precipitates. Contentand/or availability of the tartaric acid must be measured and adjustedaccordingly (if necessary) to attain a level which would not succumb,with the introduction of a calcium-based additive, to calcium tartratecrystal formation in a final, fortified product.

[0020] Precursors are, generally, but not necessarily, derived fromgrapes. Tartaric acid is relatively uncommon in nature although it isconsidered to be characteristic of grapes (Hulme, 1970; Nagy and Shaw,1980). This acid is either not found or found only in trace amounts inapple, apricot, banana, blackberry, boysenberry, cherry, cranberry,grapefruit, lemon, lime, orange, passion fruit, peach, pear, redraspberry, strawberry, tangerine, or tomato varieties (Nagy and Wade,1995). However, it sometimes appears in avocado (0.020% in tissue),mulberry, tamarind, raspberry, grapefruit (0.0003-0.0007%), or mango(Jacobs, 1951; Hulme, 1970). The natural concentration of tartaric acidin grape juice varies with grape species, variety, viticulturalpractices, geographic location of grape vineyards, climatic conditions,grape maturity, and the particular methods of juice processing. Grapevarieties are usually classified in 3 very broad color classes. Theseare white, red and black (Winkler et al., 1974). As used in thespecification and appended claims, the term “colored grape” will notrefer to the broad class of “white” grape. From these broad classes,further distinctions are made to denote green, blue and purple grapes.The coloring of the red, blue, purple and black grapes are allattributed to anthocyanin pigments, which are modified to contain aglucose molecule (Winkler et al., 1974). Tartaric levels have beenreported in the past to be nearly identical (i.e. 0.39-0.67 g/100 mls)for both white grapes and red Concord grapes (Nagy and Wade, 1995).However, there has generally been a distinction found with white grapes(e.g. Aurore, Delaware, and Niagara) that have significantly lowertartaric levels than do colored grapes (e.g. Catawba, Concord, Ives andBaco noir). These white grapes range in tartaric acid level from0.34-0.91 g/100 mls while the colored grapes range from 0.48-1.31 g/100mls (Gould, 1974). The range of tartaric acid levels for grape juicesprepared from the V. labrusca species, in particular, Concord, and forV. labrusca×V. vinifera hybrids, in particular, the variety Niagara, istypically 0.40 g/100 mls to 0.80 g/100 mls [Historical References,Welch's files].

[0021] To further differentiate the various categories of grape-basedproducts, so-called clarified grape juices are likely to be less stablewith respect to deleterious calcium tartrate formation than wouldnon-clarified juices. As part of clarification procedure, pectin isalmost completely digested by enzymes. Pectin is known to bind calcium;this can specifically be seen with diet or low calorie jams and jelliesfor which calcium is added to increase pectin-binding thereby making agel. Additionally, it has long been a nutritional concern as to thebioavailability of calcium in high fiber diets (for which pectin can bea known component) due to this known binding of ionic minerals. Thus, itis apparent that the effective elimination of pectin (i.e. in clarifiedjuices) would lead to a precursor with which any added calcium would beeven more likely to result in calcium tartrate formation (Tressler andJoselyn, 1961).

[0022] The presence of tartaric acid causes the formation of tartratecrystals in the presence of cationic species. Referring now to Table 1,this can be seen in the 100% juice blends. Calcium tartrate crystalsformed no matter what calcium source was used as an additive at tartaricacid levels of 0.21 g/100 mls or greater under storage conditions of 70°F., with the desired amount of bioavailable calcium being 35% RDI. Thus,the natural concentrations of tartaric acid found in the precursors may,of necessity, need adjustment, in order to yield stable, non-crystalforming fortified products. TABLE 1 100% Juice Blends from differentprecursors-all grape unless specified; (measured tartaric acidconcentrations) 46% conc. Grape/ 100% from 6% SS juice/ 14% SS juice/20% SS juice/ Calcium source 54% conc. Apple concentrate 94% conc. 86%conc. 80% conc. (35% RDI) (0.08 g/100 mls) (0.17 g/100 mls) (0.21 g/100mls) (0.26 g/100 mls) (0.30 g/100 mls) Calcium lactate Stable 7 weekscrystals 2 weeks crystals 2 weeks crystals 2 weeks du Gluconate:lactatedu Stable 7 weeks crystals 6 weeks Du crystals 4 weeks 60:40Gluconate:lactate du du crystals 8 weeks Du crystals 4 weeks 80:20Gluconal CAL ® Stable 16 weeks Stable 16 weeks crystals 11 weekscrystals 7 weeks crystals 3 weeks Calcium gluconate Stable 9 weeks ducrystals 12 weeks crystals 7 weeks du CCM Stable 7 weeks crystals 4weeks crystals 1 week crystals 1 week crystals 1 week

[0023] Tartaric acid content of the precursor may be adjusted by varioustechniques, in accordance with various embodiments, to form an adjustedprecursor. The concentration of single strength juices is one approach.This technique may also enhance the likelihood of natural potassiumbitartrate formation which is then removed prior to reconstitution.Grape juice, in particular, juice derived from V. labrusca and V.labrusca×V. vinifera hybrid species that has been concentrated and thenreconstituted to single strength contains approximately 75% lesstartaric acid, or from approximately 0.10 g/100 mls to 0.18 g/100 mls[Historical References, Welch's files]. An alternate technique would beto raise the pH of the precursor by adding a base. This would similarlyallow for greater tartrate ion formation and increased reactivity withnaturally occurring potassium. The pH of grape juice derived fromConcord and Niagara varieties is typically 2.8-3.7; increases in pH fromthese values will promote increased potassium tartrate formation. Inaddition to increased pH, the choice of base may also play a role. Abase may be chosen from any source having a known affinity for tartrateions and a relatively poor solubility with regard to the resultant saltformation. Temperature reductions are also known to be useful inprecipitating out tartaric acid. A reduction in temperature can reducesolubility of tartrate salts and has been used in the past, for example,in the wine industry for cold stabilization testing. Freezing can alsodramatically reduce tartaric acid levels by increasing crystal formationkinetics; thus freeze-concentration would also be a viable technique.Furthermore, reduction of tartaric acid may also be achieved viachromatographic techniques including, but not limited to, ion-exchangechromatography. A further embodiment of possible tartaric acidconcentration adjustment would simply be mixing different sources ofgrape-based liquids (e.g. colored and “uncolored/white”) or mixing grapewith non-grape liquids (including other fruit juices, water, etc.). Thefollowing are illustrative examples (in no way limiting) of non-grapejuices which this embodiment would cover: orange, apple, pear, cranberryand other berry fruits, and tropical and exotic fruits. The adjustmentof tartaric acid in the precursor may be achieved by any of the abovetechniques or combinations thereof, in addition to any other techniqueknown in the art.

[0024] In Table 1, tartaric acid concentrations were adjusted to givenmeasured values of tartaric acid by using different ratios of twoprecursors, namely, single strength grape juice (SS) and grape juicefrom concentrate (except for the 0.08 g/100 mls adjusted level whichutilized 54% apple concentrate having 0% tartaric acid). Different juicesources may be used to target specific final concentrations of tartaricacid through proper blending. Before the samples were established,initial tartaric acid concentrations were determined by High PerformanceLiquid Chromatography (HPLC) for the juice types (according to AOAC#986.13). From this, required levels of each precursor were determinedto attain a desired, adjusted concentration of tartaric acid to whichcalcium would be added (blending ratios are shown within the table). Fordesired tartaric acid concentrations less than 0.17 g/100 mls of 100%juice product, blending with a non-grape juice containing low ornegligible tartaric levels was performed, as is shown in Table 1 for0.08% tartaric acid (apple juice from concentrate was used). Afterblending, the targeted values of tartaric acid were confirmed with HPLCanalysis. After blending, targeted values of tartaric acid wereconfirmed with HPLC analysis. It should be pointed out that in measuringtartaric acid levels of the blend, the measurements were made on theadjusted precursor rather than on the final product. These precursorscontained all of the components of the final product except for thecalcium additive. This was done to obtain precise tartaric acid levelsthat are in solution without complications caused by calcium tartrateformation and the potential loss of tartaric acid solutionconcentration. Allowances were made for dilution of adjusted precursorbased on addition of calcium additive in its own, typically aqueous,carrier.

[0025] In addition to tartaric acid concentration of the precursor, theparticular calcium additive affects the final amount of bioavailable (insolution) calcium in the resulting fortified product. Not being bound bya particular theory, some stability for calcium retention (as opposed toprecipitation as tartrate) can seemingly result from a preference forcalcium to bind with a given sequestrant over the calcium binding withtartrate ions already in solution. The data in Table 1 shows that use ofcalcium gluconate in the additive leads to greater retention ofsolubility and bioavailability of calcium when compared with otheradditives. By way of example, at tartaric acid concentration of 0.21g/100 mls, products (with intended 35% RDI calcium) made with all of thetested calcium additives (namely, pure calcium gluconate, pure calciumlactate, ratios of gluconate to lactate, a specific commercial mixture,Gluconal CAL® ((which consists of a proprietary mixture of calciumgluconate and calcium lactate)), marketed by Glucona America ((Madison,Wis.)), and CCM) and stored at 70° F., exhibited calcium tartratecrystal formation. It took 11 and 12 weeks, respectively, for productmade with Gluconal CAL® and with pure calcium gluconate to revealprecipitates. Product made with CCM exhibited precipitation in only oneweek; product made with pure calcium lactate showed crystal growth inonly two weeks. Given results to date, the stability over time was shownto increase with calcium gluconate additive content for intended 35% RDIproduct. (Note: Reading down the rows of Table 1 reveals data forincreasing percentage amounts of gluconate additive, except for finalrow showing CCM result). For lower tartaric acid concentrationprecursors of 0.08 g/100 mls and of 0.17 g/100 mls, product made withany additive containing calcium gluconate shows no precipitation for atleast seven weeks. It should be noted that other, as yet untested,calcium sources may also provide acceptable levels of bioavailablecalcium without tartrate precipitation at these tartaric acid levels.These may include calcium carbonate, calcium oxide, calciumorthophosphates, calcium glubionate, calcium gluceptate, calciumlevulinate, calcium lactophosphate, calcium chloride, and mixturesthereof. Calcium lactate and, for example, calcium citrate and calciummalate, may be acceptable additives but only at either significantlyreduced levels of tartaric acid concentration in the precursor or atlower than 35% RDI intended product.

[0026] The pH also plays a critical role in facilitating tartratecrystal formation by increasing the concentration of available tartrateions. Although not shown in Table 1, all juices had a non-adjusted pH of3.0-4.0 (typically, 3.5). The pH should be as low as possible toincrease the bioavailability of the calcium source but not to minimizethe organoleptic qualities (e.g. too much sourness in low pH beverages).The juices were not adjusted due to these organoleptic requirements.

[0027] Aside from levels of tartaric acid and source of calcium, theamount of calcium also plays a contributing role. Calcium concentrationswere measured and confirmed in the product using Atomic Absorptionspectroscopy (AA). In contrast with the finding that all tested calciumadditives led to calcium tartrate crystallization at 35% RDI and 0.21 g/100 mls tartaric acid concentration (see Table 1), products fortified at20% RDI and lower have shown stablility, to date, with calcium gluconateas additive at this tartaric concentration (see Table 2). Fortifiedproducts made with Gluconal CAL® also showed stability tocrystallization for 0.30 g tartaric /100 mls at 10% RDI and lower (seeTable 2). Thus, higher concentations of tartaric acid in the fortifiedproducts can be tolerated provided that the amount of the calciumadditive (the desired bioavailable calcium level) is lowered to wellbelow 35% RDI.

[0028] Table 2 also shows results for products made with Gluconal CAL®and CCM technology at 35% RDI and 0.26g tartaric/l00mls for 100% juiceblends of apple and grape. Results are similar to those of Table 1 inthat no calcium additive at 35% RDI can remain stable at 0.26 gtartaric/100 mls. However, note that Gluconal CAL® has a greaterretention to stability than does CCM. Another comparison is shown inTable 2 for products with 100% juice blends of concord and white grapejuice at 35% RDI. Products with CCM eventually form calcium bitartratecrystals at 39 weeks for 0.15 g Tartaric/100 mls. However, noprecipitation is apparent for 99 weeks at this tartaric level usingGluconal CAL® as the additive. Table 2 also shows stability data forjuice cocktail products formulated with only 0.07 g tartaric/100 mlswhich remain stable to crystal formation for both Gluconal CAL® andcalcium lactate. At this very reduced tartaric acid level, economics mayplay a role in determining which additive to use. Calcium lactate is avery inexpensive additive. TABLE 2 g Tartaric/ Fortified Product % RDI100 mls Calcium tartrate formation results 100% grape juice w/Calciumgluconate 35% 0.21 Crystals 12 weeks 100% grape juice w/Calciumgluconate 20% 0.21 Stable 8 weeks 100% grape juice w/Calcium gluconate10% 0.21 Stable 8 weeks 100% grape juice w/Calcium gluconate  8% 0.21Stable 8 weeks 100% grape juice w/Gluconal CAL ® 35% 0.30 Crystals 2weeks 100% grape juice w/Gluconal CAL ® 20% 0.30 Crystals 4 weeks 100%grape juice w/Gluconal CAL ® 10% 0.30 Stable 17 weeks 100% grape juicew/Gluconal CAL ®  8% 0.30 Stable 17 weeks 100% grape/apple juice blend35% 0.26 Crystals 8 weeks w/Gluconal CAL ® 100% grape/apple juice blend35% 0.26 Crystals 1 week w/CCM technology 30% white grape cocktail 35%0.07 Stable 26 weeks w/ Gluconal CAL ® 30% white grape cocktail 35% 0.07Stable 26 weeks w/calcium lactate 100% Concord and white grape blend 35%0.15 Stable 52 weeks w/Gluconal CAL ® 100% Concord and white grape blend35% 0.15 Crystals 39 weeks w/CCM

[0029] Batch processing for manufacture of calcium-fortified grapeliquids has been performed under four distinct conditions. Theseparticular processing runs are detailed below.

[0030] Batch Process A:

[0031] A one gallon aqueous batch of calcium gluconate additive wasprepared by dispersing 63.17 g of calcium gluconate (monohydrate) into2673.2 g of water. 252.6 g of SS Concord grape juice (15.3 Brix) wasblended separately, with 1059.1 g of Concord concentrate (57.2 Brix), toadjust the tartaric acid level of the SS juice. 2.15 g of ascorbic acidwas also added. The calcium gluconate aqueous solution was added to thefruit juice solution under rapid mixing. After mixing, samples werebottled in 16 oz. glass bottles and heated in bottles to 195° F. topasteurize. After pasteurization, Brix, titratable acidity, pH, %tartaric acid (measured with HPLC) and % calcium (measured with AA) weremeasured. Results were 17.5 Brix, pH 3.6, 0.52% titratable acidity (ascitrate), 0.21 g tartaric/100 mls, and 350 mg/8 ounces calcium. Sampleswere stored in a 70° F. chamber and weekly visual inspection was done toobserve for any crystal formation. Additionally, monthly samplings wereperformed for Brix, titratable acidity, pH, sensory, and filtering(specifically for tartrate crystals).

[0032] Batch Process B:

[0033] A plant scale, batch process experiment was done using GluconalCAL®.

[0034] Components Include:

[0035] a) Welch's Concord grape juice concentrate—V. labrusca (Brix at57.0° to 68.0° and tartaric acid at 0.10 g/10 ml as single strengthjuice).

[0036] b) White grape juice concentrate—V. vinifera (Brix at 57.0° to68.0° as a concentrate and tartaric acid at 0.9 g/100 ml to 0.24 g/100mlas single strength from concentrate was obtained from Canandaigua(Madera, Calif.)).

[0037] c) 1.14% (w/w) solubilized Gluconal CAL® from Glucona America(Madison, Wis.).

[0038] d) Brix of 4° to 25° preferably 12° to 20.

[0039] e) water.

[0040] The sequence of addition during product batching, filtration,heat processing, filling and cooling particular to this embodimentinvolve specific methodology. Prior to batching the grape juice, a 25%aqueous solution of Gluconal CAL® was prepared. Note that calciumgluconate may have been used alone but would, due to limited solubility,have required a lower aqueous concentration. For this batch,approximately 158.9 lbs. of water at 125° F. −135° F. was added to a55-gallon mixing vessel. The water was agitated using a high speed mixer(≧3600 rpm) prior to the addition of the calcium-based additive. About52.9 lbs. of Gluconal CAL® was rapidly added (in less than 1 minute) tothe 55 gallon vessel. The solution was allowed to mix for at least 2minutes. Brix was measured and determined at 25.0% to 25.3%. The finalweight of the solution was approximately 211.8 lbs. For a 1200-gallonbatch, the following amounts of ingredients were required; 2055 lbs. ofConcord grape juice concentrate, 875 lbs. or white grape juiceconcentrate, 512 lbs. of 25% Gluconal CAL®, 2304 grams of ascorbic acid,18 lbs. of citric acid and 7231 lbs. of filtered water. The juice wasbatched in the following order of addition: concentrate, calciumsolution, filtered water, citric acid and ascorbic acid. The batch wasallowed to mix with slow to moderate agitation for 15-30 minutes priorto measuring Brix and titratable acidity. The batch as adjusted withwater and acid to meet product targets for Brix (17.4±0.3) andtitratable acidity (0.58±0.02 g/100 g).

[0041] To obtain maximum clarity, the juice was filtered through apressure leaf filter that has been pre-coated with a sufficient amountof diatomaceous earth filter cel. Each leaf of the filter contains atleast ⅛″ coating of filter cel. The grade of cel was JM503, FW20,Dicalite Speedex or equivalent. The juice was polish filtered through aplate and frame filter using JM503, FW20, Dicalite Speedex, orequivalent as the filter aid. The product was recycled until thefiltrate was 100% free of any filter aid or other sediment.

[0042] The filtered juice product was pumped through a plate heatexchanger at a flow rate of 144 gallons per minute and heated to atemperature of 180° F. The product was held for 14 seconds and thenfilled into 64 fl. oz. PET bottles. After filling, the product wastransferred to a cooling tunnel and cooled to a temperature of 105° F.

[0043] The result of this method is a 100% grape juice, which containsadded optional ingredients (e.g. ascorbic acid for vitamin C and citricacid for tartness). It is calcium fortified at 300 mg/8 fl. oz. serving(or 30% RDI).

[0044] Batch Process C:

[0045] Calcium lactate was used to fortify white grape juice cocktailusing the following components:

[0046] a) 10-30% White grape concentrate.

[0047] b) 0-20% Single strength, clarified Niagara grape juice

[0048] c) Brix of 4° to 250 preferably 12° to 20°

[0049] d) 0.24% to 1.07% (w/w) solubilized calcium lactate (i.e. 8 to35% RDI)

[0050] e) 2-10% 42F corn syrup

[0051] f) 1-8% sugar

[0052] g) citric acid, ascorbic acid, and sodium citrate as necessary toadjust flavor and nutrition (generally <1% each)

[0053] h) water

[0054] Calcium lactate was significantly less stable with tartaric acidconcentrations than calcium gluconate. Thus, a much lower tartaric acidconcentration had to be achieved. This was accomplished by utilizingwhite grape concentrate and single strength clarified Niagara grapejuice, which would yield 0.07 g/100 mls tartaric acid at 30% juice.Typical tartaric acid concentration for white concentrate is 0.097 g/100mls while SS white grape juice has 0.4 g/100 mls. For a 15 gallon batch,a base was prepared consisting of 6.73 kg SS Niagara, 3.09 kg whitegrape concentrate, 3.50 kg 42F corn syrup, 2.74 kg sugar, 194.1 g citricacid, 22.5 g sodium citrate and 2 kg water. This base was then dilutedwith 41.16 kg of water and then 27.2 g of ascorbic acid and 612.3 g ofcalcium lactate were added and mixed thoroughly. Target juice parameterswere 0.07 g/100 mls tartaric acid and 350 mg Calcium/8 ounce servings.

[0055] Samples were stored at 32°, 70°, and 90° F. for 26 weeks with novisible calcium tartrate formation.

[0056] Batch Process D:

[0057] Gluconal CAL® was used to fortify a blend of apple and grapejuice utilizing the following components:

[0058] a) 5-46% Basic grape concentrate

[0059] b) 54-95% apple concentrate

[0060] c) Brix of 4° to 25° preferably 12° to 20°

[0061] d) 0.24% to 1.07% (w/w) solubilized Gluconal CAL® (i.e. 8 to 35%RDI)

[0062] e) water

[0063] Tartaric acid would only be 0.08 g/100 mls with 100% juice bythis formulation. This is due to basic concentrate having approximately0. 17 g/100 mls tartaric acid and 46% of this component would yield 0.08g/100 mls tartaric. Apple concentrate has negligible to zero tartaricacid thus 0.08 g/100 mls would be the amount in a 100% juice blend atthese ratios.

[0064] One gallon batches were prepared by dispersing 52.76 g ofGluconal CAL® into 200 g of water. 518.3 g of SS Concord grape juice(57.2 Brix) were blended separately with 349.1 g of apple concentrate(70.3 Brix); and 2884.9 g water and 2.15 g of ascorbic acid were added.The Gluconal CAL® aqueous solution was added to the fruit juice solutionunder rapid mixing. After mixing, samples were bottled in 16 oz. glassbottles and heated in bottles to 185° F. to pasteurize. Afterpasteurization, Brix, titratable acidity, pH, % tartaric acid (HPLC) and% calcium (AA) were all measured. Results were 14.1 Brix, pH 3.6, 0.48%titratable acidity (as citrate), 0.08 g tartaric/100 mls, and 350 mg/8ounces calcium. Samples were stored in a 70° F. chamber and weeklyvisual inspection was done to observe for any crystal formation.

[0065] Although the invention has been described with reference toseveral embodiments, it will be understood by one of ordinary skill inthe art that various modifications can be made without departing fromthe spirit and the scope of the invention, as set forth in the claimshereinbelow.

We claim:
 1. A method of making a fortified, tartaric acid-containingproduct, the product fortified with a predetermined amount ofbioavailable calcium, the product essentially free of tartrateprecipitates, the method comprising: providing a tartaricacid-containing precursor; adjusting tartaric acid concentration of theprecursor to form an adjusted precursor; and mixing the adjustedprecursor with an additive, the additive comprising: a calcium-basedcompound.
 2. A method according to claim 1 wherein, in providing, thetartaric acid-containing precursor is a liquid.
 3. A method according toclaim 2 wherein, in providing, the tartaric acid-containing precursor isa grape-based liquid.
 4. A method according to claim 1 wherein, inproviding, the tartaric acid-containing precursor is derived fromcolored grapes.
 5. A method according to claim 1 wherein, in providing,the tartaric acid-containing precursor has a tartaric acidconcentration, the concentration being between approximately 0.005 g per100 mls and approximately 1.31 g per 100 mls.
 6. A method according toclaim 1 wherein the predetermined amount corresponds to at least 8% ofrequired daily intake for a human.
 7. A method according to claim 6wherein the predetermined amount corresponds to approximately 35% ofrequired daily intake for a human.
 8. A method according to claim 7wherein, in adjusting, the adjusted precursor has a measured, adjustedtartaric acid concentration, the measured, adjusted tartaric acidconcentration being no greater than 0.17 g per 100 mls.
 9. A methodaccording to claim 1 wherein, in mixing, the calcium-based compound isselected from calcium gluconate, calcium carbonate, calcium oxide,calcium orthophosphate, calcium glubionate, calcium lactate, calciumgluceptate, calcium levulinate, calcium lactophosphate, calcium citrate,calcium chloride, calcium malate, calcium phosphate, calcium disodiumEDTA, and combinations thereof.
 10. A method according to claim 9wherein, in mixing, the-calcium-based compound is selected from calciumgluconate, calcium lactate, and combinations thereof.
 11. A methodaccording to claim 10 wherein, in mixing, the calcium-based compound iscalcium gluconate.
 12. A method according to claim 8 wherein, in mixing,the calcium-based compound comprises calcium gluconate.
 13. A methodaccording to claim 12 wherein the product, when stored at a temperatureof approximately 70° F., remains essentially free of tartrateprecipitate for at least sixteen weeks.
 14. A method according to claim4 wherein the predetermined amount corresponds to at least 8% ofrequired daily intake for a human.
 15. A method according to claim 14wherein, in adjusting, the adjusted precursor has a measured, adjustedtartaric acid concentration, the measured, adjusted tartaric acidconcentration being no greater than 0.17 g per 100 mls.
 16. A methodaccording to claim 15 wherein the calcium-based compound comprisescalcium gluconate.
 17. A method according to claim 16 wherein theproduct, when stored at a temperature of approximately 70° F., remainsessentially free of tartrate precipitate for at least sixteen weeks. 18.A fortified, tartaric acid-containing product processed according toclaim
 1. 19. A fortified, tartaric acid-containing product processedaccording to claim
 8. 20. A fortified, tartaric acid-containing productprocessed according to claim
 12. 21. A fortified, tartaricacid-containing product processed according to claim
 16. 22. A method ofmaking a fortified, tartaric acid-containing product comprising:providing a tartaric acid-containing precursor, the precursor comprisingbetween approximately 0.005 g per 100 mls and approximately 0.26 g per100 mls. of tartaric acid, and mixing the precursor with a predeterminedamount of an additive, the additive comprising: calcium gluconate; suchthat bioavailable calcium in the product is no more than approximately20% of required daily intake of calcium for a human.
 23. A methodaccording to claim 22 wherein, in providing, the precursor is a liquid.24. A method according to claim 23 wherein, in providing, the precursoris a grape-based liquid.
 25. A method according to claim 22 wherein, inproviding, the precursor is derived from colored grapes.
 26. Afortified, tartaric acid-containing product processed according to claim22.
 27. A method according to claim 2 wherein, in adjusting, theadjusted precursor is formed by adding a second precursor to the liquidtartaric acid-containing precursor.
 28. A method according to claim 27wherein, in adjusting, the second precursor is single strength grapejuice.
 29. A fortified, tartaric acid-containing product processedaccording to claim
 27. 30. A method according to claim 28 wherein, inadjusting, the second precursor is single strength white grape juice andthe liquid tartaric acid-containing precursor is white grapeconcentrate.
 31. A method according to claim 30, wherein, in adjusting,the adjusted precursor has a measured, adjusted tartaric acidconcentration and, in adjusting, water is added so that the measured,adjusted tartaric acid concentration is no greater than approximately0.08 g per 100 mls.
 32. A method according to claim 31, wherein, inmixing, the calcium-based compound is selected from calcium gluconate,calcium carbonate, calcium oxide, calcium orthophosphate, calciumglubionate, calcium lactate, calcium gluceptate, calcium levulinate,calcium lactophosphate, calcium citrate, calcium chloride, calciummalate, calcium phosphate, calcium disodium EDTA, and combinationsthereof.
 33. A method according to claim 32 wherein, in mixing, thecalcium-based compound is selected from calcium gluconate, calciumlactate, and combinations thereof.
 34. A method according to claim 33wherein, in mixing, the calcium-based compound is calcium lactate.
 35. Afortified, tartaric acid-containing product processed according to claim33.
 36. A fortified, tartaric acid-containing product processedaccording to claim
 34. 37. A method of making a fortified, tartaricacid-containing product, the product fortified with bioavailable calciumin an amount equaling approximately 35% of required daily intake for ahuman, the product essentially free of tartrate precipitates, the methodcomprising: providing a tartaric acid-containing precursor derived fromcolored grapes; adjusting tartaric acid concentration of the precursorto form an adjusted precursor; and mixing the adjusted precursor with anadditive, the additive comprising: calcium gluconate.
 38. A methodaccording to claim 37 wherein, in adjusting, the adjusted precursor hasa measured, adjusted tartaric acid concentration, the measured, adjustedtartaric acid concentration being no greater than 0.17 g per 100 mls.39. A fortified, tartaric acid-containing product processed according toclaim
 37. 40. A method of making a fortified, tartaric acid-containingproduct, the product fortified with bioavailable calcium in apredetermined amount equaling between approximately 8% and approximately35% of required daily intake for a human, the product essentially freeof tartrate precipitates, the method comprising: providing a tartaricacid-containing precursor derived from white grapes; adjusting tartaricacid concentration of the precursor to form an adjusted precursor, theadjusted precursor having a measured, adjusted tartaric acidconcentration, the measured, adjusted tartaric acid concentration beingno greater than 0.08 g per 100 mls; and mixing the adjusted precursorwith an additive, the additive comprising: calcium lactate.
 41. Afortified, tartaric acid-containing product processed according to claim40.